1. Field of the Invention
This invention relates to apparatus for exhibiting grains of precious stone.
2. Description of the Prior Art
Small particles consisting of grains of precious stone are used for various purposes. They may be used as parts of tools, such as grinding wheels, grinding belts or arcuate abrasive members. Diamond grains are mainly used for said purposes.
Grains of precious stone may also be used as ornament or for advertising purposes.
Grains having specified properties are required for certain purposes. In the previous practice, grains have been kept in boxes or in so-called diamond papers in order to exhibit material which is suitable for a certain purpose. In that case the grains of precious stone constitute an aggregation so that their shape and their optical activity under special conditions, e.g., conditions of illumination, are not readily apparent.